If you continually lose, then yes, it'll hit zero. The best way I've found is to remove all your equipment, set all your percentages to 0 besides 1 randomly chosen value, which would be 100%. Then just fight alot of people who are around the same rank as you are until you lose enough to get to zero >.>

Don't fight people more experienced than youDon't fight people stronger than youDon't fight people faster than youDon't fight people smarter than you... wait.. no.. fight people smarter than you, they are ussually nerds

You're all missing the obvious here....just hack into every other player's account, remove any pvp gear, set one defense to 0%, and then ATTACK! You'll be at the top of the leaderboard (or banned) in no time.